This is a feature request. The function org-capture-finalize allows an argument to 'jump-to-capture'. I think it may be a good idea to add a new argument to 'kill-buffer' after the capture is finalized. This would be useful to avoid having to kill the capture buffer manually. I assume that if ':kill-buffer' is intended as the default behavior, then it would be better to set it in the capture template.
I mean something like 'C-u C-u C-c C-c'. I can't think now of a better way to do it. Any idea is welcome. Thanks for your work.